7. DNA and Chromosome Structure
Bacterial and Viral Chromosome Structure
Bacteria and Viral Chromosome Structure
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Hi in this video we're gonna be talking about bacterial and viral chromosome structure. So bacterial viral chromosomes are much simpler. So they have very different characteristics than eukaryotic chromosome. So for instance bacterial genetic material circular and it's pretty much just D. N. A. Whereas viral genetic material can be single or double stranded and it can be D. N. A. Or RNA. And in eukaryotic it's usually not circular. Right? It's organized into chromosomes its D. N. A. It's always double stranded and much more complex than either of these two. But one of the similar things between eukaryotic D. N. A. And bacterial and viral is that there are DNA binding proteins that do exactly what they sound like they do. They bind to the D. N. A. Now the two really important ones in bacteria are H. U. N. H. One and these aren't found in eukaryotic chromosomes exactly. But they're a similar protein to what we call histone proteins which we'll talk about soon that are found in eukaryotic chromosomes. Um And these are super important in packaging that D. N. A. Into a small area because even though the D. N. A. Isn't as complex it's still a lot of D. N. A. For such a tiny bacteria or virus and that has to be packaged really tightly is to be squished together really tightly and the only way to do that is through proteins, the DNA doesn't do it by itself. And so these proteins are really important in packaging that D. N. A. Now a circular chromosome isn't just the circle with nothing on it. Right. It has jeans but it also has some few structural components. Important. One is the origin of replication which doesn't which is exactly what it sounds like, right? It's where replication starts. Um But there are also jeans on there and regulatory areas and there are repetitive sequences actually. Now they're much so smaller and bacterial chromosomes and viral chromosomes than they are in eukaryotic. But they do have these repetitive sequences that exist and often in bacteria. They're an inter genic regions and these are the regions between the genes that are not transcribed and although it's not completely known. But it's believed that maybe these may act as regulatory units affecting gene expression and bacteria. Um very similar to how these units act actually in humans as well. So that's just a brief overview of bacterial and viral chromosome structure. Let's not move on.
True or False:Bacteria and viruses can use RNA as their genetic material.
What is the name of the bacterial chromosomal region where replication begins?
Transcription start site
Origin of DNA copying
Polymerase initiation site
Origin of replication
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PRACTICE PROBLEMS AND ACTIVITIES (7)
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- How many base pairs are in a molecule of phage T2 DNA 52-µm long?
- Following is a diagram of the general structure of the bacteriophage chromosome. Speculate on the mechanism by...
- To gauge the fidelity of DNA synthesis, Arthur Kornberg and colleagues devised a technique called nearest-neig...